the analytical detection limit of 0.02 inicrogram per litre 

 (yg/L). The reported value of 0.06 Ug/L observed on August 8, 

 was anomalous, but still is much less than the proposed objective of 

 0.2 Ug/L. Uranium data for 1984 are unavailable for the East 

 Poplar River at the International Boundary but based on historical 

 data are believed to be typical of background concentrations found 

 in surface waters. 



Cookson Reservoir 



Data submitted quarterly by Saskatchewan Environment indicate that 

 the TDS and boron concentrations of Cookson Reservoir discharge 

 remained below 1 000 and 2.5 mg/L, respectively. The observed boron 

 and TDS concentrations at the sampling site in the reservoir near 

 the dam are generally somewhat higher than those observed at the up- 

 stream station near Highway 36, during 1984. As follow-up to its 

 work in September 1983, Environment Canada conducted further sampling 

 for mercury in water and sediment of Cookson Reservoir during 1984. 

 Preliminary results on the samples indicate mercury levels in water 

 to be below the analytical detection limit. A detailed report on 

 the results of these mercury analyses is in preparation. 



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